sha1.putString("The quick brown fox jumps over the lazy dog", Charsets.UTF_8)
            .hash()
            .toString());
    assertThrows(IllegalStateException.class, () -> sha1.hash());
  }

  public void testToString() {
    assertEquals("Hashing.md5()", Hashing.md5().toString());
    assertEquals("Hashing.sha1()", Hashing.sha1().toString());

  public void testCreateFromHashMultimap() {
    Multimap<Double, Double> hash = HashMultimap.create();
    hash.put(1.0, 2.0);
    hash.put(2.0, 3.0);
    hash.put(3.0, 4.0);
    hash.put(4.0, 5.0);

    TreeMultimap<Double, Double> copyFromHash = TreeMultimap.create(hash);
    assertEquals(hash, copyFromHash);
    assertEquals(Ordering.natural(), copyFromHash.keyComparator());

    String init = "d41d8cd98f00b204e9800998ecf8427e";
    assertEquals(init, Hashing.md5().newHasher().hash().toString());

    String asciiHash = "e5df5a39f2b8cb71b24e1d8038f93131";
    assertEquals(asciiHash, Files.hash(asciiFile, Hashing.md5()).toString());

    String i18nHash = "7fa826962ce2079c8334cd4ebf33aea4";
    assertEquals(i18nHash, Files.hash(i18nFile, Hashing.md5()).toString());
  }

  public void testMap() throws IOException {

import com.google.common.annotations.GwtCompatible;
import com.google.common.collect.testing.SampleElements.Colliders;
import java.util.List;

/**
 * A generator using sample elements whose hash codes all collide badly.
 *
 * @author Kevin Bourrillion
 */
@GwtCompatible
@ElementTypesAreNonnullByDefault
public abstract class TestCollidingSetGenerator implements TestSetGenerator<Object> {
  @Override

        adjust = ~~adjust;
        // in GWT, we have to deal with integer overflow carefully
      }
      int hash = 1;
      for (Set<E> axis : axes) {
        hash = 31 * hash + (size() / axis.size() * axis.hashCode());

        hash = ~~hash;
      }
      hash += adjust;
      return ~~hash;
    }
  }

  /**
   * Returns the set of all possible subsets of {@code set}. For example, {@code

    // hash to the different values.
    assertThat(InetAddresses.getCoercedIPv4Address(InetAddresses.forString("2002:0102:0304::1")))
        .isNotEqualTo(
            InetAddresses.getCoercedIPv4Address(InetAddresses.forString("2002:0506:0708::1")));

    // 2 6to4 addresses NOT differing in the embedded IPv4 address should
    // hash to the same value.

   */
  @Override
  boolean equals(@CheckForNull Object object);

  /**
   * Returns the hash code for this graph. The hash code of a graph is defined as the hash code of a
   * map from each of its {@link #edges() edges} to the associated {@link #edgeValueOrDefault(N, N,
   * V) edge value}.
   *

  boolean equals(@CheckForNull Object object);

  /**
   * Returns the hash code for this multiset. This is defined as the sum of
   *
   * <pre>{@code
   * ((element == null) ? 0 : element.hashCode()) ^ count(element)
   * }</pre>
   *
   * <p>over all distinct elements in the multiset. It follows that a multiset and its entry set
   * always have the same hash code.
   */
  @Override
  int hashCode();

  /**

import javax.annotation.CheckForNull;
import org.checkerframework.checker.nullness.qual.Nullable;

/**
 * Implementation of ImmutableBiMap backed by a pair of JDK HashMaps, which have smartness
 * protecting against hash flooding.
 */
@GwtCompatible(emulated = true)
@ElementTypesAreNonnullByDefault
final class JdkBackedImmutableBiMap<K, V> extends ImmutableBiMap<K, V> {
  @VisibleForTesting

import com.google.common.base.Charsets;
import com.google.common.collect.ImmutableList;
import com.google.common.collect.ImmutableSet;
import com.google.common.collect.Iterables;
import com.google.common.hash.Hashing;
import com.google.common.io.Closer.LoggingSuppressor;
import com.google.common.primitives.UnsignedBytes;
import com.google.common.testing.TestLogHandler;
import java.io.ByteArrayOutputStream;